The present invention relates in general to semiconductor devices and, more particularly, to semiconductor devices having a backside coating that is patterned to provide information pertaining to the semiconductor.
Electronics system manufacturers continue to demand lower cost integrated circuits and other semiconductor devices in order to reduce the cost of electronics systems. In response, many semiconductor manufacturers are providing unpackaged semiconductor dice or chips which can be mounted in a “flip-chip” fashion with the active die surface attached directly to system circuit boards. This approach reduces the direct cost of the semiconductor devices and also improves their performance by reducing lead inductance and other parasitic elements. However, the “flip-chip” technique often increases the indirect costs because such an unpackaged semiconductor chip reveals little or no information pertaining to the type of die such as its part number or manufacturer. In case of a system malfunction, it is difficult to trace a defect to a particular manufacturer or fabrication process.
To avoid this problem, some chips are fabricated with a thick backside surface coating whose surface is marked with information about the semiconductor device to facilitate tracing the device to its manufacturer in the event of a defect. Other chips use a gold coating which is etched to provide the desired pattern. However, these approaches result in the information having a low contrast and therefore low visibility, in some cases even when viewed through a microscope or other visual tool. To compensate for the low contrast, the prior art coatings are marked with large fonts, which reduces the amount of information that can be provided, especially on a small die. As a result, the ability to trace a defective semiconductor device to a specific processing step is reduced, making it more difficult to prevent future defects that could enhance the die yield and reliability to reduce the overall fabrication cost of the device and system.
Hence, there is a need for a semiconductor device and method of providing easily discernible information pertaining to the semiconductor device in order to reduce the fabrication cost and increase the reliability of the semiconductor device.